Gritstone bio, Inc. announced that the first patient has been enrolled for inclusion in the Phase 2/3 GRANITE-CRC-1L trial. The trial evaluates the individualized neoantigen vaccine GRANITE in combination with immune checkpoint blockade for the first line (1L) maintenance treatment of newly diagnosed patients with metastatic, microsatellite-stable colorectal cancer (MSS-CRC). This trial has registrational intent and has been discussed previously with the FDA.

Additionally, the company reported updated overall survival (OS) data from its Phase 1/2 GRANITE trial evaluating individualized immunotherapy in combination with nivolumab (OPDIVO®) and ipilimumab (YERVOY®) in patients with advanced solid tumors, specifically end-stage metastatic MSS-CRC. Patients with MSS-CRC who experienced a molecular response (as evidenced by a decrease in circulating tumor DNA [ctDNA]) continue to have an OS advantage compared to those patients who did not have a molecular response. All patients alive at the time of the ESMO 2021 data presentation remain alive after an additional ~22 weeks of follow-up (January 5, 2022 data cut-off).

Gritstone will address these developments and present the updated OS data (from the Phase ½ trial in patients with advanced solid tumors) in a presentation at the 40th Annual JP Morgan Healthcare Conference occurring at 8:15am ET on January 13, 2021. About GRANITE-CRC-IL Phase 2/3 Trial: The GRANITE-CRC-1L trial (NCT05141721) is a Phase 2/3, randomized, open-label study evaluating the GRANITE individualized immunotherapy regimen as a first line (1L) maintenance treatment in combination with atezolizumab (TECENTRIQ®) and ipilimumab (YERVOY®) in newly diagnosed patients with metastatic, microsatellite-stable colorectal cancer (MSS-CRC) who received fluoropyrimidine, oxaliplatin and bevacizumab (FOLFOX-bevacizumab) induction therapy. The Phase 2 portion of the study will measure changes in ctDNA over time to characterize the clinical activity of maintenance therapy with GRANITE (GRT-C901/GRT-R902).

The Phase 3 portion will further measure the clinical efficacy of the regimen as assessed by progression-free survival using iRECIST criteria. About Phase 1/2 Trial Evaluating GRANITE Against Advanced Solid Tumors: The purpose of this study was to evaluate the safety, dose, immunogenicity and early clinical activity of the GRANITE individualized neoantigen cancer vaccine, in combination with OPDIVO® (nivolumab) and YERVOY® (ipilimumab), in patients with end-stage metastatic MSS-CRC, NSCLC, gastroesophageal adenocarcinoma, and urothelial cancer (NCT03639714).